Ventilator for chimney stacks and the like



y 8, 1950 o. w. PETERSON VENTILATOR FOR CHIMNEY STACKS AND THE LIKEFiled March 18, 1949 2 Sheets-Sheet l JNVENTOR. ORWIN W. PETERSONATTORNEYS J 1950 o. w. PETERSON 2,515,467

VENTILATOR FOR CHIMNEY STACKS AND THE LIKE Filed March 18, 1949 2Sheets-Sheet 2 l I IINIIHI 4 JNVENTOR.

ORWIN W. PETERSON ATTORNEYS Patented July 18, 1950 VENTILATOR FORCHIMNEY STACKS AND THE LIKE Orwin W. Peterson, Denver, Colo.

Application March 18, 1949, Serial No. 82,228

This invention relates to ventilators for chimney stacks and the like.

Particularly when the wind direction changes quite frequently, or evenwhen a hard wind is blowing, it often happens that a gust of wind, oreven a sustained wind, will cause a down draft into a chimney, stack orthe like. The resultant reverse flow of gases in a chimney or stack notonly tends to interfere with burning or combustion, as in a furnaceor'flreplace, but also may produce a fire hazard. The latter may beoccasioned by sparks or live coals blown from a fireplace into a room,or by the extinguishment of a gas flame and the possible escape of unlitgas, with a consequent danger of explosion. Caps or covers, spacedupwardly from the stack or chimney top, have not solved the problemsuccessfully, since a wind blowing across the opening at the top maytend to enter the chimney. Also, if one side of the chimney, as on thatof the prevailing wind, is protected by a shield or the like, a changein wind direction tends to render such shield valueless,

Among the objects of the present inventionare to provide a novelventilator for a chimney, stack or the like; to provide such aventilator which will produce an up draft at the chimney or stackopening; to provide such a ventilator which will produce such an udraft, irrespective of wind direction or changes in wind direction; toprovide such a ventilator'which can be easily and cheaply manufactured,and be made in various sizes so as to fit any desired stack or chimney;to provide such a ventilator which will contain a minimum of parts; toprovide such a ventilator which will produce a minimum of'waste materialduring the manufacture thereof; and to provide such a ventilator whichwill require a minimum of time for the production thereof. Other objectsand the novel features of this invention will become apparent fromthedescription which follows, taken in connection with the accompanyingdrawings, in which;

Fig. 1 is a side elevation of a ventilator constructed in accordancewith this invention, in stalled on the upper end of a chimney or stackplp Fig. 2 is a horizontalsection'taken along line 2--2ofFig.1;

Fig. 3 is a generally vertical section, with certain parts broken away,illustrating the interior construction of the ventilator'of Fig. '1;

Fig. 4 is atop plan view, on a reduced scale, of a skirt blank cut from'a single sheet of material, such skirt forming a part of the ventilatorof Fig. 1; and

Fig. 5 is an enlarged transverse section taken through a lock joint, atwhich the ends of the skirt blank are attached together.

' A v ntilator constructed-i a ordance with 7 Claims. (Cl. 9878) thisinvention, as illustrated in Figs. 1 and 2, may comprise a top T and askirt S, or outer wall, mounted one above the other and installed on achimney or stack pipe P, which also may be termed an inner member. Thepipe P will normally be formed of sheet metal or the like, and is alsousually circular in form, although the ventilator of this invention maybe installed on chimneys, stacks or pipes having other than a circularcross section. The skirt S is generally tubular but is larger indiameter or size than and extends in spaced relation to the pipe P, bothabove and below the top ID of pipe P, and may diverge slightly from topto bottom. In accordance with this invention, the lower portion of skirtS, spaced below the top of pipe P, is provided with a series of airchannels or scoops l I, such as four in number, and preferably equallyspaced about the periphery thereof, as apart, each air channel I Iextending generally upwardly from the bottom of the skirt S toward thetop H! of the pipe P, but terminating below the top In. Each air channelI I is adapted to catch and then direct wind and air currents toward andthen around and upwardly from the pipe top Ill. The current of airproduced by a channel H will tend to carry hot gases or smoke from thepipe P, along with it, in the enlarged space within skirt S above pipetop It, as by a suction effect.

Each air channel II is bounded by a forwardly inclined and radiallyextending edge l2 to provide an exterior opening, into which wind or aircurrents flow from primarily one direction only, andmay be formed by aflange l3 which has a transversely curved bottom or rear wall and whichextends inwardly at an angle and then upwardly along the pipe P. Eachflange I3 is preferably integral with skirt S, although one or more'maybe formed separately and attached'to the skirt. Also, the skirt S ispreferably cut away at each flange I3, to form the edges l2, each ofwhich is downwardly inclined and slopes in a direction with respect tothe vertical, which is opposite to the direction of slope ofthe'bottomof the air channel. The flange l3 'foreach air channel, as in Fig. 3, ispreferably formed. by a generally trapezoidal tongue I4, shown inextended position in dottedlines in Fig. 3, which is bent upwardly andinwardly so that the point l5 thereof can be lappedover onto the upperend ID of pipe P. The upper inside section l6 of tongue I4 is alsopreferably formed to flt against the pipe P. i

As will be evident from Figs. 1 to 3,'inclusive, the'wind or air currentblowing into one of the air channels II is conducted interiorly of theskirt and past the pipe top 10, but each of the other air channels I Iwill tend to prevent'or retard the flow of air thereinto, so that forany particular wind direction, one orperhaps two air channels II willreceive the air current. Due to the substantially equal spacing of theair channels II, and the capacity of each air channel to catch wind orair current blowing primarily in one direction only, or from one side ofthe chimney or stack, whenever the wind direction changes or shifts, asthrough approximatel 90 degrees, the previous air channel will tend nolonger to conduct the air, but one of the other air channels will catchand direct the air upwardly, and around the pipe top 10. As will beevident, there will thus always be one or more air channels [I toreceive the wind or air current, irrespective of the wind direction.

The top T of the ventilator may be formed from a pair of frustro-conicalplates l8 and [9, respectively, plate It being disposed in uprightposition and its outer edge preferably having a greater diameter thanthe skirt S. The plate I9 is inverted within the plate I8, the outeredge of plate l9 preferably engaging the plate 88 and having a diameterslightly less than that of the upper edge of skirt S. The plates is and[9 are preferably attached together in any suitable manner, as by spotwelding, each preferably being formed from a single sheet bent or rolledaround to final shape and the edges then attached to-- gether, as byriveting or welding, although each of the conical plates l3 and i9 maybe formed from a solid sheet or plate extruded or otherwise formed fromflat plate. The top T is supported in spaced position above the skirt 3,as by a series of relatively narrow supports 20, such as three or fourin number. The lower ends of supports 20 may be attached to the upperedge of the skirt S by metal screws 2|, or in any other suitable manner,as by riveting, spot welding or the like. Also, the upper ends of thesupports 20 may be bent to conform to the shape of one of the plates 18or H), and attached thereto by riveting, spot welding or by metal screwsor the like.

The space between the upper edge of skirt S and the top T is preferablysuch that the current of air directed upwardly from one or more of theair channels H and the gases from pipe P will strike the smaller plate18 and be deflected outwardly from underneath the larger plate l9, itbeing understood, of course, that the wind or natural air currentblowing between the skirt S and top '1 will tend to carry off smoke andhot gases from pipe P, along with the air current from the channel I lto the leeward side.

In further accordance with this invention, the skirt S is preferablymade from a single sheet in a, simple, effective and economical manner,as

in Fig. 4, which is shown on a reduced scale in comparison with Figs.1-3. The sheet is preferably cut so that an upper are 23 will have alength equal to the circumference of the upper edge of the skirt S,while the ends 24 and 25 extend radially from the are 23, allowancebeing made for the ends to lap over and form a joint, such as the lockjoint 26 of Fig. 5. The lower are 21 of the sheet of Fig. 4 ispreferably laid out from the same center as the upper are 23, and spacedradially a sufficient distance to accommodate not only the verticalheight of the skirt '3, but also additional material to form the tongues14, which are produced by triangular cut-outs 28. The upper end points29 of the triangular cut-outs 28 are preferably spaced equidistantlyfrom each other, and from the end 25 of the sheet. The longer edge 30 ofeach cutout 28 preferably extends from the upper end point 29 to a pointon the lower are 21 radially beneath the next adjacent point 29, whilethe shorter edge 3| of each triangular cut-out diverges from the longeredge 30 at a suitable angle, depending upon the relative size of theskirt and the size and shape of the air channels II to be produced.After the skirt sheet has been cut out, the ends 24 and 25 are lappedover and locked together, one or more rivets also being utilized ifdesired. The central portion of each tongue 14 is bent around in asuitable curve, starting along a line generally perpendicular to thelonger edge 30 of the adjacent cut-out, such as alon the dash lines 32.Prior to or at the time of installation of the ventilator, the point I5of each tongue may be bent over and clinched on the pipe top H), eachpoint I5 being bent along a suitable line, such as the dash line 33 ofFig. 4. The shorter edge 3| of each cut-out, as in Fig. 3, will thenextend vertically along the wall of pipe P, and each tongue or flange l3may be fastened to the pipe adjacent to the lower end of edge 3|, as bya metal screw 34 of Figs. 2 and 3, or in any other suitable manner. Theholes for the metal screws may, of course, be drilled prior toinstallation of the ventilator on the pipe, although the position andnumber of screws may be varied, as desired. Preferably, skirt S is cutout, attached together, the tongues I4 bent to shape, and the top Tattached thereto, prior to installation of the ventilator on the pipe P.However, if desired, the ventilator may be made directly on a section ofpipe, which may then later be placed in or installed on the stack orchimney.

Instead of the tongue M adjacent end 24 requiring a portion of the lockjoint, the tongue may be made at the left, such as the tongue l4, shownin dotted outline; and the tongue I l at the right omitted, the sheetbeing cut away along the dotted extension 35 of the adjacent edge 3|. Inthis way, it is unnecessary to form the lock joint 26 across one of thetongues 14. The shaping and installation of the skirt, with the tongueI4, is essentially the same as described above.

For laying out the skirt sheet, as in Fig. 4, whenever a number ofskirts or ventilators of the same size are to be made, it will beadvantageous to make a template of the correct size and shape, forlaying out a number of skirts, either on separate sheets or plate or thesame sheet or plate. Or, a larger template including a number of skirtlayouts may be made. Of course, when the quantity to be producedwarrants, dies for cuttin out the skirt sheets by machine may be made.Both the skirt S and top T of the ventilator may be made of suitablematerial, such as from galvanized steel sheet or plate, or other metal,such as aluminum, copper, etc. Normally, the ventilator will be made ofthe same or similar material .as the pipe P, but this is not alwaysnecessary. Also, the ventilator may be made on a section of the pipe P.in the shop, and the section then attached to the remainder of the pipe,as by a conventional interfitting slip joint or the like.

From the foregoing it will be evident that the ventilator of thisinvention fulfills to a marked degree the requirements and objectshereinbefore set forth. The operation of the ventilator is not affectedby changes in wind or air current direction or velocity, since even themost varying and whipping gusts will usually not change the productionof the upwardly directed air current which travels through one or morechannels H,

and upwardly and around the pipe top I0. Also, any change or shift inwind direction will merely cause another of the channels II to producethe desired upward current inside the skirt, instead of the channel ilinto which the wind previously passed.

The production of the ventilator of this invention is quite simple andeconomical. A minimum of labor and assembly cost is involved, since theparts are few in number, assembly requires only a few rivets or metalscrews, and installation requires only the placement of a few metalscrews or the like. The utilization of the tongues M to form not onlythe air channels I I, but also to attach the ventilator to the pipe P ina sturdy yet simple manner, contributes considerably to the low cost ofmanufacture. The production of the skirt S from a single sheet of metal,merely by making a few triangular cut-outs, after properly shaping theedges, lends itself to maximum production operations, since the skirtscan be cut out in quantities by dies, if desired. Since chimney pipescome in a few generally standard sizes, it will be necessary only tomake up a template for the skirt S of each specific size, and the timerequired to produce the skirt from the template should be very smallindeed. The shaping of the tongues to form the air channels 1 l is arelatively simple operation, since the sheet may be held in place by ajig or the like, and the tongues I4 bent up in turn, either to engagethe edge of the pipe P on which the particular ventilator is beinginstalled, or to engage a dummy pipe, for purposes of manufacture.

As will be evident, there is relatively little scrap in the sheet fromwhich the skirt S is made, and a minimum of attaching screws and thelike is necessary. Also, the curvature of the tongues is notcomplicated, and there are no really diflicult geometrical patterns toproduce. It will be understood, of course, that the skirt S may be madefrom more than one piece of metal, if desired, such as two or morepieces attached together, although production from a single sheetinvolves less labor time. However, if a relatively large ventilator,such as several feet in diameter, is to be produced, it may be desirableto make the skirt from more than one piece of metal, and also addstiffening bars or angles, if advantageous.

Although a specific embodiment of this invention has been illustratedand described with particularity, and various changes indicated, it willbe understood that other changes may be made therein, and also thatother embodiments may exist, all without departing from the spirit andscope of this invention.

What is claimed is:

1. A ventilator for a stack or the like, comprising an inner tubularmember; a generally tubular outer wall mounted in spaced encompassingrelation to said inner member, said wall extending upwardly to a pointabove the upper end of said inner member and downwardly to a point belowthe upper end of said inner member; and a plurality of flanges extendingfrom the lower end of said wall generally inwardly to said inner memberand then upwardly along said inner member and secured thereto, each saidflange extending downwardly, then inwardly and upwardly at an anglebetween said wall and inner tubular member, so as to form an air channelbetween said wall and inner member, said flanges being spaced apart toform inlets for said air channels.

2. A ventilator for a stack or the like, as defined in claim 1, whereinsaid outer wall is cut away at each said flange to form a downwardlyinclined edge sloping in a direction with respect to the vertical,opposite the direction of slope of said air channel bottom with respectto the vertical.

3. A ventilator for a stack or the like, as defined in claim 1, whereinthe upper end of each said flange is bent over the top of said innermember.

4. A ventilator for a stack or the like, as defined in claim 1, whereinthe highest point of the inwardly extending portion of each said flangeis spaced below the upper end of said inner member.

5. A ventilator for a stack or the like, as defined in claim 1, whereineach said flange is integral with said outer wall.

6. A ventilator for a stack or the like, as defined in claim 1, whereinsaid flanges are four in number and circumferentially spaced apart.

7. A ventilator for a stack or the like, comprising an inner tubularmember; a generally tubular outer wall mounted in spaced encompassingrelation to said inner member, said wall extending upwardly to a pointabove the upper end of said inner member and downwardly to a point belowthe upper end of said inner member; a plurality of flanges extendingfrom the lower end of said wall generally inwardly to said inner memherand then upwardly along said inner member and secured thereto, each saidflange extending downwardly, then inwardly and upwardly at an anglebetween said wall and inner tubular member, so as to form an air channelbetween said wall and inner member, said flanges being spaced apart toform inlets for said air channels; and a top mounted on the upper end ofsaid wall and extending laterally beyond said wall.

ORWIN W. PETERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 199,399 Barnum Jan. 22, 18781,074,143 Vaughn et al Sept. 30, 1913 1,489,886 Hart et al Apr. 8, 19241,545,618 Sundahl July 14, 1925 1,849,812 Spencer Mar. 15, 1932 FOREIGNPATENTS Number Country Date 3,198 Great Britain Feb. 13, 1893 10,514Great Britain 1886 821,078 France Aug. 17, 1937

